z-Transform Example -Determine the z-transform X(z) of the causal sequence xn]=a"[n] and its ROC NoWX(z)=∑am]zn=∑a" n=0 The above power series converges to X(=)= 1-0-1, for az<1 ROC is the annular region >a Copyright C 2001, S K MitraCopyright © 2001, S. K. Mitra 10 z-Transform • Example - Determine the z-transform X(z) of the causal sequence and its ROC • Now • The above power series converges to • ROC is the annular region |z| > || x[n] [n] n =   =   =   = −  =− − 0 ( ) [ ] n n n n n n X z n z z , for 1 1 1 ( ) 1 1   − = − − z z X z